I’m looking at buying either the William Optics Zenithstar f6.9 81mm or the Sky Watcher Black diamond 80mm f7.5
the intended purpose is visual. I’m wanting one that is sharp and no field curvature with my Naglar 20mm and pan optics 27mm eyepiece
my question is how much better corrected will the Skywatcher be over the WO since it has a slower focal ratio of 7.5.
I recently tried a 72mm f5.9 and it had plenty of field curvature with my eyepieces. I did not care for it much